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Worksheet Grade 7 English Language Arts

Explaining Brine Disposal at the Pipperton Desalting Plant

A grade 7 explanatory writing worksheet that has students repair a vague draft about what an inland reverse osmosis plant does with its leftover salty water.

Objectives

  1. Students will define a technical term in plain language without using the term itself.
  2. Students will replace vague nouns, pronouns, and verbs with precise ones from a fact sheet.
  3. Students will write an explanatory paragraph that reports options without arguing for one.

Vocabulary

Key words: explanatory, concentrate, brackish, membrane, appositive, transition

Teacher overview

Pipperton is a fictional inland town that treats salty groundwater with membranes, so it ends up holding the salt it removed and has to decide where the salt goes. This worksheet gives students a deliberately vague draft about that problem and repairs it one craft move at a time, ending in a paragraph students assemble themselves. The teaching note worth making first is that many students treat explanatory writing as argument writing with the opinion sentence left in, which is why the draft contains a stray recommendation and why two items exist to remove it. A second misconception belongs to the content rather than the craft: students often assume that a filter destroys what it removes, when a membrane only moves salt from one stream of water into another.

Explaining Brine Disposal at the Pipperton Desalting Plant — Grade 7 English Language Arts
Name: ____________________________ Date: ______________

Student Worksheet

Pipperton is a fictional town, and the plant, the wells, and the creek below were written for this worksheet. Read the fact sheet, then work on the draft.

Fact sheet: the Pipperton Desalting Plant

  • Pipperton pumps brackish groundwater from the Pipperton well field. Brackish water is saltier than fresh water and less salty than seawater. The raw water carries about 1,800 mg/L of dissolved salt.
  • The plant pushes that water at high pressure against membranes. The membranes hold back most of the salt and let cleaner water through.
  • For every 100 gallons the plant treats, about 75 gallons leave as drinking water and about 25 gallons leave as a salty stream called concentrate, or brine.
  • The salt is not destroyed. Nearly all of it ends up in the concentrate.
  • Pipperton sits far from the coast, so it cannot pipe the concentrate to the ocean. The town is studying three options.
  • Option one, a deep injection well. Crews pump the concentrate far below the drinking water aquifer. Drawback: the town must monitor the well for many years to show that nothing leaks upward.
  • Option two, lined evaporation ponds. The concentrate sits in shallow ponds until the water evaporates and the salt is trucked away. Drawback: the ponds would cover about 60 acres of land the town does not own.
  • Option three, a permitted discharge to Stannery Creek. The town would release small amounts of concentrate under a state permit. Drawback: the creek runs low in late summer, so the salt would be less diluted in exactly the season fish are most stressed.

A student's first draft

(1) The Pipperton plant makes water. (2) It uses membranes to take out the salt stuff. (3) Then there is leftover water with the salt in it. (4) They have to do something with it. (5) I think the ponds are clearly the best idea. (6) It gets put somewhere. (7) That is how the plant works.

Items

  1. Sentence 5 does not belong in an explanatory paragraph. Explain why in one sentence.
  2. Write a one-sentence definition of "concentrate" for a reader who has never seen the word. Do not use the word "concentrate" inside your definition.
  3. Rewrite sentence 2 using precise nouns from the fact sheet in place of "the salt stuff."
  4. Sentence 6 uses a vague pronoun and a vague verb. Rewrite it so a reader learns what moves and where it could go.
  5. Put these four stages in the order the fact sheet gives them: treated water goes to homes in Pipperton; brackish water comes up from the well field; the salt leaves the plant in the concentrate; pumps push the water against the membranes.
  6. Choose the transition that fits the gap between sentences 3 and 4, and explain your choice in one sentence: "For example," "Because of that," or "In contrast."
  7. Write a topic sentence for a paragraph whose subject is what Pipperton does with its concentrate.
  8. Write one sentence that uses a figure from the fact sheet and names the fact sheet as the place the figure came from.
  9. Write a sentence that defines "brackish" using an appositive, which is a naming phrase set off by commas right after the word.
  10. Choose one of the three options. Write two sentences that explain how it works and state its drawback. Do not say whether Pipperton should choose it.
  11. Sort these two sentences into explanatory and argument: "The ponds would cover about 60 acres." "The town should refuse to build ponds on land it does not own."
  12. Write a closing sentence for the paragraph that tells the reader what still has to be decided.
  13. Using your work from items 2 through 12, write an explanatory paragraph of five or more sentences about what happens to the salt at the Pipperton plant. Use the words "membrane," "concentrate," and "aquifer," and include no opinion.

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key
  1. Answer: Sentence 5 states an opinion and recommends one option, while an explanatory paragraph reports how something works and leaves the choosing to the reader. Accept any answer naming the opinion or the recommendation.
  2. Answer: Accept any accurate one-sentence definition that avoids the word. A strong response reads something like, "It is the salty stream of water left over after the membranes pull most of the salt out of the water the plant treats." Withhold credit if the definition uses the word being defined.
  3. Answer: Accept any rewrite naming dissolved salt and the membranes, such as, "The plant pushes the water against membranes that hold back most of the dissolved salt." Credit requires a precise noun in place of "stuff."
  4. Answer: Accept any rewrite that names the concentrate and one destination, such as, "The concentrate is pumped into a deep injection well, held in lined evaporation ponds, or released to Stannery Creek under a permit." Credit requires both a named substance and a named place.
  5. Answer: Brackish water comes up from the well field; pumps push the water against the membranes; treated water goes to homes in Pipperton; the salt leaves the plant in the concentrate. Accept the last two in either order only if the student explains that the two streams leave at the same time.
  6. Answer: "Because of that." Sentence 4 states a result of sentence 3, and only that transition signals a result. "For example" would promise an example and "In contrast" would promise an opposite.
  7. Answer: Accept any topic sentence that names the concentrate and the decision, such as, "Because Pipperton sits far from the coast, the town has three ways to handle the salty water its plant leaves behind." Credit requires a stated subject rather than a title.
  8. Answer: Accept any sentence that reports a figure accurately and attributes it, such as, "According to the plant fact sheet, about 25 of every 100 gallons treated leave as concentrate." Withhold credit if the figure is changed or if no attribution appears.
  9. Answer: Accept any correct appositive, such as, "Brackish water, water saltier than a river and less salty than the sea, fills the Pipperton well field." Credit requires the naming phrase set off by commas directly after the term.
  10. Answer: Accept any two sentences that match one option in the fact sheet and name its stated drawback, with no recommendation. A strong response reads something like, "In a deep injection well, crews pump the concentrate far below the aquifer that supplies drinking water. The town would then have to monitor that well for many years to show nothing leaks upward."
  11. Answer: The first sentence is explanatory and the second is argument. The first reports a measurement a reader could check, while the second tells the town what to do.
  12. Answer: Accept any closing sentence that names an open question, such as, "Pipperton has not yet decided which option to build, and each one carries a cost the town would live with for years." Withhold credit if the sentence recommends an option.
  13. Answer: Accept any explanatory paragraph of five or more sentences that uses all three required words, reports the process accurately, and contains no opinion. A strong response opens with the well field, moves through the membranes, names the two streams that leave the plant, states that the salt ends up in the concentrate, and closes with the open decision. Withhold full credit if a recommendation appears or if the paragraph says the salt is removed from the world rather than moved into another stream.

Differentiation

Support

Give these students the fact sheet with the three options printed on separate cards, so item 10 becomes a matter of reading one card rather than searching a page. Model item 3 aloud with a different vague noun, naming the two questions "What is it?" and "What is it made of?" before rewriting. Reduce item 13 to four sentences and supply the first one.

Extension

Ask these students to write a second paragraph that explains why an inland town faces a harder disposal problem than a coastal one, using only information stated or implied in the fact sheet. A second option is to rewrite the student draft twice, once as explanatory writing and once as argument writing, then to mark every sentence that had to change and say why.

ELL supports

Pre-teach "membrane," "brackish," "concentrate," "aquifer," and "evaporate" with a simple labeled drawing showing water entering a membrane and two streams leaving it. Provide the frames "According to the fact sheet, " and " is ___, which means ___" for items 8 and 9. Allow students to complete item 5 by numbering cut-apart strips rather than copying the stages, and to answer item 11 by circling rather than writing.

Extensions

Have students turn the paragraph from item 13 into a short notice a utility could mail to customers, keeping every fact and cutting the word count roughly in half. Then have them write two sentences naming what they cut and what a reader loses by not seeing it, which is the same judgment a public information officer makes when a technical decision has to fit on one page.